Regulatable triggers for pneumatic devices

ABSTRACT

This invention relates to a regulatable air supply device for use with pneumatic tools and provides a trigger slidably mounted in a sleeve which is rotatably mounted within a shell, the sleeve being provided with at least one bore which may be overlapped in varying degrees with a complementary bore in the shell by manual rotation of the sleeve within the shell, whereby to vary selectively the size of the orifice formed by the overlapping bores.

United States Patent 11 1 Brown [54] REGULATABLE TRIGGERS FOR PNEUMATIC DEVICES [76] Inventor: James L. Brown, 106 Carriage Square Drive, St. Louis County, Mo. 63141 221 Filed: Dec. 7, 1970 211 App1.No.: 95,611

[52] US. Cl. ..l37/637.4, l37/614.17, 137/614.19 [51] Int. Cl ..F16k 1/00 [58] Field of Search ..l37/614.l7; 415/203; l37/614.l6, 614.19, 625.49, 637, 637.5,

[56] References Cited UNITED STATES PATENTS 3,280,842 10/1966 Weisenbach ..137/625.69

[ 51 Jan. 2, 1973 3,326,240 6/1967 McConnaughay ..137/637.4 1,372,915 3/1921 Smith 1,152,213 8/1915 Phillips ..137/614.l7

Primary Examiner-Martin P. Schwadron Assistant Examiner-R. G. Nilson Attorney-Joseph A. Fenlon, Jr.

[57] ABSTRACT This invention relates to a regulatable air supply device for use with pneumatic tools and provides a trigger slidably mounted in a sleeve which is rotatably mounted within a shell, the sleeve being provided with at least one bore which may be overlapped in varying degrees with a complementary bore in the shell by manual rotation of the sleeve within the shell, whereby to vary selectively the size of the orifice formed by the overlapping bores.

2 Claims, 4 Drawing Figures PATENIEUJM 2mm SHEET 1 [1F 2 FIG. 2

INVENTOR JAMES L BROWN ATTY PATENTEU 2575 3.707 994 sum a nr 2 REGULATABLE TRIGGERS FOR PNEUMATIC DEVICES It is the object of this invention to provide a simple means for quickly and manually regulating the amount of air delivered to the air driven members of pneumatic tools.

With the above and other objects in view, which will become immediately apparent upon reading the specifications, my invention resides in the unique and novel form, arrangement, construction and combination of parts shown in the drawings, explained in the specifications, and claimed in the claims.

In the drawings:

FlG. l is a side elevational view of a pneumatic tool which is provided with a preferred embodiment of my invention;

FIG. 2 is a fragmentary sectional view taken along lines 22 of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view taken along the same aspect as FIG. 2;

FIG. 4 is an exploded view of the trigger valve mechanism with the shell shown in section for clarity.

CONSTRUCTION Referring now in more detail and by reference character to the drawings, which illustrate a preferred embodiment of my invention, A designates a pneumatic too] including a handle 10 and a main body 12 provided with a driven end 14. Since my invention is combinable with all pneumatic tools, it suffices to say for the purpose of this specification that the contents of the body 12 comprise a conventional impact wrench and the end 14 comprises a conventional socket attachment. Mounted on the handle 10 is a hose attachment plug 16 which receives one end (not shown) of a pneumatic supply hose (also not shown). Also mounted in a threaded bore 18 in the handle 10 is a manually adjustable trigger valve 20. A first passageway 22 establishes pneumatic communication between the attachment plug 16 and the bore 18, and a second passageway 24 establishes pneumatic communication between the bore 18 and the air inlet 26 to the main body 12.

The trigger valve 20 comprises a shell 30, an inner sleeve 32, a plunger 34, and a biasing spring 36. The shell 30 includes a hexagonal head 38, a set of external threads 40, an external annular recess 42, a reamed axially extending inner bore 44 and a pair of diametrally opposed radial bores 46, 48 which provide communication between the inner bore 44 and the annular recess 42. The threads 40 are sized for mating with the threads of the bore 18, the recess 42 is located at the juncture of the bore 18 and the passageway 24, and the bores 46, 48 are located in the approximate center of the -recess 42, all as best seen in FIGS. 3 and 4.

The inner sleeve 32 (shown in section in FIG. 4 for purposes of clarity) comprises an elongated cylindrical portion 50 sized for snug fitting disposition in the inner bore 44, an annular flange 52 located at one end, an annular recess 54 located at the other end, an inner bore 56 which extends axially from front to back, and a pair of diametrally opposed radially extending bores 58, 60, which provide communication between the inner bore 56 and the external portion 50, as shown. The recess 54 is sized for accepting a spring clip 62 which retains the sleeve 32 within the shell 30, and the bores 58, 60, are

located for axial registration with the bores 46, 48, when the sleeve 32 is disposed within the shell 30, and an O-ring seat 64 is provided at the inner end of the inner bore 56, all for purposes presently more fully to appear.

The plunger 34 includes a cylindrical stem 66 sized for snug-fitting disposition in the inner bore 56, a centrally located neck 68, an intermediate cylindrical element 70 which is diametrally larger than the neck 68 but diametrally smaller than the stem 66, an end portion 72 which is the same diametral size as the stem 66,

and an O-ring seat 74 located between the element 70 and the end 72. On the outer end the plunger is provided with an enlarged button 76.

When the plunger 34 is installed in the inner bore 56, and an O-ring 78 is disposed in the seat 74, the radial projection of the O-ring 78 cooperates with the O-ring seat 64 in the sleeve 32 to provide a fluid seal and to hold the plunger 34 in the sleeve 32 as shown. The biasing spring 36 which is conventionally disposed between the back wall of the bore 18 normally biases the O-ring 78 against the seat 64 to keep the trigger valve 20 normally closed.

OPERATION Air under pressure is provided to the back of the bore 18 through the attachment plug 16 and the passageway 22. The trigger valve 20 is held in the normally closed position by the biasing spring 36.

The trigger valve 20 provides for air regulation to the air supplied to the air inlet 26 of the main body 12. It will be noted that the position of the shell 30 always remains fixed with respect to the handle 10. It should also be noted, however, that the sleeve 32 is rotatable with respect to the shell 30. By rotating the sleeve 32 in the shell 30, the degree of overlap of the bores 46, 48 in the shell 30 and the bores 58, 60 in the sleeve 32 may be selectively varied, and the amount ofair which passes from the back of the bore 18 into the air inlet 26 when the plunger 34 is urged inwardly may thus be regulated. Indicia means on the head 38 of the shell 30 (not shown) and cooperating indicia means on the flange 52 of the sleeve 32 (also not shown) may be utilized to advise the operator of the relative degree of overlap of the bores 46, 48, 58, 60, if desired.

It should be understood that changes, alterations and modifications in the form, construction, arrangement, combination of various parts of my invention herein shown may be made and substituted without departing from the nature and principle of my invention.

Having thus described my invention what I claim and desire to secure by Letters Patent is recited in the specifications, shown in the drawings and claimed in the claims.

I claim:

1. A pneumatic tool control device comprising means for supplying air under pressure from an external source to a work chamber within a housing, and a regulatable trigger valve mounted in a bore within said housing,

said housing including a first passageway establishing pneumatic communication between the bore and the work chamber and a second passageway establishing pneumatic communication between the bore and the external source, and said trigger valve including a cylindrical shell removably secured to the housing and being provided with a diametrally reduced annular neck portion at the intersection of the first passageway and the bore,

a first radially extending port located in the annular neck portion of the shell, a coaxial cylindrical sleeve rotatably mounted in the shell and being provided with a second radially extending port, and a plunger slidably mounted in the sleeve and spring biased against the housing to a normally closed position between the first passageway and second passageway,

said first and second ports being substantially the 2. The device of claim 1 wherein the sleeve is rotatably secured to the shell. 

1. A pneumatic tool control device comprising means for supplying air under pressure from an external source to a work chamber within a housing, and a regulatable trigger valve mounted in a bore within said housing, said housing including a first passageway establishing pneumatic communication between the bore and the work chamber and a second passageway establishing pneumatic communication between the bore and the external source, and said trigger valve including a cylindrical shell removably secured to the housing and being provided with a diametrally reduced annular neck portion at the intersection of the first passageway and the bore, a first radially extending port located in the annular neck portion of the shell, a coaxial cylindrical sleeve rotatably mounted in the shell and being provided with a second radially extending port, and a plunger slidably mounted in the sleeve and spring biased against the housing to a normally closed position between the first passageway and second passageway, said first and second ports being substantially the same size and being located at substantially the same axial position on the common axis of the shell and the sleeve, whereby as the sleeve is rotated within the shell the degrees of overlap between the first and second ports may be selectively varied and the size of the resultant aperture between the external source and the work chamber may be selectively varied.
 2. The device of claim 1 wherein the sleeve is rotatably secured to the shell. 